Electrochemical cell

Abstract

An electrolytic cell (1) is provided with a metal support (10) and a cell main body (20). The metal support (10) further has an air-permeable region (10a) in which a plurality of communication holes (11) are formed, and an air-impermeable region (10b) surrounding the air-permeable region (10a). A hydrogen electrode layer (6) of a cell main body section (20) has a first region (6a) formed on a gas-permeable region (10a), and a second region (6b) formed on a gas-impermeable region (10b). The average particle diameter of Ni contained in the second region (6b) is smaller than the average particle diameter of Ni contained in the first region (6a).

Description

Technical Field

[0001] This invention relates to electrochemical single cells. Background Technology

[0002] Previously, electrochemical single cells (electrolytic single cells, fuel cells, etc.) having a metal support and a single cell body disposed on the metal support are known (see, for example, Patent Document 1).

[0003] The metal support has: a breathable area with multiple interconnected holes, and an impermeable area that surrounds the breathable area when viewed from above.

[0004] The main body of the single battery includes: a first electrode layer formed on a metal support; a second electrode layer; and an electrolyte layer disposed between the first electrode layer and the second electrode layer. The first electrode layer includes: a first region formed on a permeable region of the metal support, and a second region formed on an impermeable region of the metal support.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-155337 Summary of the Invention

[0008] When an electrochemical single cell is used in the form of a stack of multiple layers, the second region of the first electrode layer is located on the side of the stack. Therefore, its temperature is easily reduced due to heat dissipation towards the external atmosphere, and gas is not easily supplied to the second region through the connecting holes. Consequently, electrode reactions are less likely to occur in the second region compared to the first region, leading to a current distribution that easily occurs between the first and second regions, resulting in the degradation of the first electrode layer.

[0009] The objective of this invention is to improve the electrochemical single cell that can suppress the degradation of the first electrode layer.

[0010] The electrochemical single cell according to a first aspect of the present invention comprises a metal support and a single cell body. The metal support has: a permeable region having a plurality of connecting holes, and an impermeable region surrounding the permeable region when viewed from above. The single cell body is disposed on the metal support. The single cell body has: a first electrode layer containing Ni; a second electrode layer; and an electrolyte layer disposed between the first electrode layer and the second electrode layer. The first electrode layer has: a first region formed on the permeable region and a second region formed on the impermeable region. The average particle size of Ni contained in the second region is smaller than the average particle size of Ni contained in the first region.

[0011] The electrochemical single cell according to the second aspect of the present invention, based on the first aspect described above, has a second region with a greater porosity than the first region.

[0012] Effects of the Invention

[0013] According to the present invention, an electrochemical single cell capable of suppressing the degradation of the first electrode layer can be provided. Attached Figure Description

[0014] Figure 1 This is a plan view of the electrolytic single cell involved in the implementation method.

[0015] Figure 2 yes Figure 1 AA section diagram. Detailed Implementation

[0016] (Electrolytic single cell 1)

[0017] Figure 1 This is a plan view of the electrolytic single cell 1 involved in the implementation method. Figure 2 yes Figure 1 A cross-sectional view of AA. Electrolytic single cell 1 is an example of the "electrochemical single cell" involved in this invention.

[0018] The electrolytic cell 1 is formed as a plate extending in both the X-axis and Y-axis directions. In this embodiment, the electrolytic cell 1 is formed as a rectangle extending along the Y-axis direction when viewed from above. However, the planar shape of the electrolytic cell 1 is not particularly limited and can be a polygon, ellipse, circle, etc., other than a rectangle. It should be noted that the X-axis and Y-axis directions are examples of planar directions.

[0019] like Figure 2 As shown, the electrolytic single cell 1 includes: a metal support 10, a single cell body 20, and a flow path component 30.

[0020] [Metal Support 10]

[0021] The metal support 10 supports the main body 20 of the single cell. The metal support 10 is formed in the shape of a plate. The metal support 10 can be flat or curved. The metal support 10 only needs to be able to support the electrolytic single cell 1, and its thickness is not particularly limited. For example, it can be more than 0.1 mm and less than 2.0 mm.

[0022] like Figure 2 As shown, the metal support 10 has: multiple connecting holes 11, a first main surface 12 and a second main surface 13.

[0023] Each connecting hole 11 extends from the first main surface 12 to the second main surface 13, penetrating the metal support 10. Each connecting hole 11 is open on both the first main surface 12 and the second main surface 13. The opening on the first main surface 12 side of each connecting hole 11 is covered by the hydrogen electrode layer 6. The opening on the second main surface 13 side of each connecting hole 11 is connected to the flow path 30a described later.

[0024] Each connecting hole 11 can be formed using machining (e.g., stamping), laser processing, or chemical processing (e.g., etching). Furthermore, if the metal support 10 is made of porous metal, each connecting hole 11 can be a connecting hole formed by the opening pores of the porous metal. Each connecting hole 11 may be perpendicular to the first main surface 12, may not be perpendicular to the first main surface 12, and may not be linear.

[0025] A single battery body portion 20 is joined to the first main surface 12. A flow path component 30 is joined to the second main surface 13. The first main surface 12 is located on the opposite side of the second main surface 13.

[0026] like Figure 2 As shown, the metal support 10 has a breathable region 10a and an impermeable region 10b. The breathable region 10a is the area in the metal support 10 where multiple connecting holes 11 are formed. The impermeable region 10b is the area in the metal support 10 other than the breathable region 10a. The impermeable region 10b surrounds the breathable region 10a when viewed from above in the Z-axis direction, which is perpendicular to the X-axis and Y-axis directions. Accordingly, as Figure 2 As shown, in the cross-section of the metal support 10 along the Z-axis, the airtight region 10b appears on both sides of the airtight region 10a.

[0027] like Figure 2 As shown, the boundary between the breathable region 10a and the impermeable region 10b is defined by the openings of the first and second connecting holes 11a and 11b located on the outermost side in the X-axis direction. Specifically, the boundary between the breathable region 10a and the impermeable region 10b is defined by a first reference line 11S and a second reference line 11T. The first reference line 11S is: passing through the outermost position P1 in the X-axis direction of the opening on the first main surface 12 side of the outermost first connecting hole 11a, and parallel to the Z-axis direction. Figure 2 The second reference line 11T is a straight line perpendicular to the first main surface 12. It is a line that passes through the outermost position P2 in the X-axis direction of the opening of the second supply hole 11b, which is furthest from the first supply hole 11a on the side of the first main surface 12, and is parallel to the Z-axis direction. Figure 2In the middle, a straight line (perpendicular to the first main surface 12). The area between the first reference line 11S and the second reference line 11T in the metal support 10 is the breathable area 10a, and the area in the metal support 10 other than the breathable area 10a, that is, the area on both sides of the breathable area 10a, is the non-breathable area 10b.

[0028] The metal support 10 is made of a metallic material. For example, the metal support 10 is made of an alloy material containing Cr (chromium). Examples of such metallic materials include Fe-Cr alloy steel (stainless steel, etc.) and Ni-Cr alloy steel. There is no particular limitation on the Cr content in the metal support 10, and it can be 4% by mass or more and 30% by mass or less.

[0029] The metal support 10 may contain Ti (titanium) and Zr (zirconium). There is no particular limitation on the Ti content in the metal support 10; it can be 0.01 mol% or more and 1.0 mol% or less. There is no particular limitation on the Al content in the metal support 10; it can be 0.01 mol% or more and 0.4 mol% or less. The metal support 10 may contain Ti in the form of TiO2 (titanium dioxide) or Zr in the form of ZrO2 (zirconium oxide).

[0030] The metal support 10 may have an oxide film formed by oxidizing the constituent elements of the metal support 10 on its surface. For example, a chromium oxide film is a representative example. The chromium oxide film covers at least a portion of the surface of the metal support 10. Additionally, the chromium oxide film may cover at least a portion of the inner wall surface of each connecting hole 11.

[0031] [Single battery body part 20]

[0032] The main body 20 of a single cell is disposed on a metal support 10. The main body 20 of the single cell includes: a hydrogen electrode layer 6 (cathode), an electrolyte layer 7, an anti-reaction layer 8, and an oxygen electrode layer 9 (anode).

[0033] The hydrogen electrode layer 6, electrolyte layer 7, anti-reaction layer 8, and oxygen electrode layer 9 are stacked sequentially in this order along the Z-axis, which is perpendicular to the X-axis and Y-axis, starting from the side of the metal support 10. The hydrogen electrode layer 6, electrolyte layer 7, and oxygen electrode layer 9 are mandatory components, while the anti-reaction layer 8 is optional.

[0034] [Hydrogen Polar Layer 6]

[0035] A hydrogen electrode layer 6 is formed on the metal support 10. The hydrogen electrode layer 6 is disposed between the metal support 10 and the electrolyte layer 7. The hydrogen electrode layer 6 is supported by the metal support 10. Specifically, the hydrogen electrode layer 6 is disposed on the first main surface 12 of the metal support 10. The hydrogen electrode layer 6 is an example of the "first electrode layer" of the present invention.

[0036] The feed gas is supplied to the hydrogen electrode layer 6 through each connecting hole 11. The feed gas contains at least H2O.

[0037] When the feed gas contains only H2O, the hydrogen electrode 6 generates H2 from the feed gas according to the electrochemical reaction of water electrolysis given by equation (1) below.

[0038] Hydrogen electrode layer 6: H2O + 2e － →H2+O2 － ···(1)

[0039] When the feed gas contains H2O and CO2, the hydrogen electrode layer 6 generates H2, CO and O2 from the feed gas through a co-electrolysis electrochemical reaction as given in equations (2), (3) and (4) below. － .

[0040] Hydrogen electrode layer 6: CO2 + H2O + 4e － →CO + H₂ + 2O₂ － ···(2)

[0041] Electrochemical reaction of H2O: H2O + 2e － →H2+O2 － ···(3)

[0042] • Electrochemical reaction of CO2: CO2 + 2e － →CO+O2 － ···(4)

[0043] The hydrogen electrode layer 6 is a porous body with electronic conductivity. The hydrogen electrode layer 6 contains nickel (Ni). In co-electrolysis, Ni functions as an electron conductor and also as a thermal catalyst, promoting the thermal reaction between the generated H2 and the CO2 contained in the feed gas, thus maintaining an appropriate gas composition for metallization, anti-aqueous gas transfer reactions, etc. The Ni contained in the hydrogen electrode layer 6 exists primarily as metallic Ni during the operation of the electrolytic cell 1; however, it may also exist partially as nickel oxide (NiO).

[0044] The hydrogen electrode layer 6 can contain ion-conducting materials. These ion-conducting materials can include YSZ, CSZ, ScSZ, GDC, SDC, (La,Sr)(Cr,Mn)O3, (La,Sr)TiO3, Sr2(Fe,Mo)2O6, (La,Sr)VO3, (La,Sr)FeO3, LDC (lanthanum-doped cerium oxide), LSGM (lanthanum gallate), and mixed materials combining two or more of these materials.

[0045] The Ni content in the hydrogen electrode layer 6 is not particularly limited and can be between 20 vol% and 50 vol%. The Ni content is calculated using the following method. First, a cross-section of the hydrogen electrode layer 6 along the Z-axis is exposed. Next, using a SEM apparatus (FE-SEM JSM-7900F manufactured by Nippon Electron Ltd.) and the EDS apparatus (JED-2300) attached to the SEM apparatus, a compositional mapping image of Ni in the cross-section of the hydrogen electrode layer 6 is acquired at 5000x to 10000x magnification. Next, using Image-Pro image analysis software manufactured by MEDIACYBERNETICS, binarization is performed using image analysis to identify Ni particles in the Ni compositional mapping image. Then, the total area of ​​Ni particles is divided by the total area of ​​the hydrogen electrode layer 6 in the backscattered electron image (including pores) to calculate the Ni content in the hydrogen electrode layer 6.

[0046] The content of ion-conducting material in the hydrogen polar layer 6 is not particularly limited and can be above 20 vol% and below 50 vol%. The content of ion-conducting material is calculated using the following method. First, using the aforementioned SEM and EDS apparatus, a compositional mapping image of the element with the highest content (hereinafter referred to as the "maximum content element") among the constituent elements of the ion-conducting material in the cross-section of the hydrogen polar layer 6 is obtained at 5000 to 10000x magnification. Next, using the aforementioned image analysis software Image-Pro, binarization processing is performed using image analysis to determine the particle portion of the maximum content element in the compositional mapping image of the maximum content element. Then, the total area of ​​the particle portion of the maximum content element is divided by the total area of ​​the hydrogen polar layer 6 (including pores) in the backscattered electron image, thereby calculating the content of ion-conducting material in the hydrogen polar layer 6.

[0047] There are no particular limitations on the thickness of the hydrogen electrode layer 6; for example, it can be greater than 1 μm and less than 100 μm.

[0048] like Figure 2 As shown, the hydrogen electrode layer 6 has a first region 6a and a second region 6b. The first region 6a is the region in the hydrogen electrode layer 6 formed on the permeable region 10a of the metal support 10. The second region 6b is the region in the hydrogen electrode layer 6 formed on the impermeable region 10b of the metal support 10. The second region 6b surrounds the first region 6a when viewed from above in the Z-axis direction. Accordingly, as Figure 2 As shown, in the cross-section of the hydrogen pole layer 6 along the Z-axis, the second region 6b appears on both sides of the first region 6a.

[0049] The boundary between the first region 6a and the second region 6b is defined by the first reference line 11S and the second reference line 11T mentioned above. The region between the first reference line 11S and the second reference line 11T in the hydrogen electrode layer 6 is the first region 6a, and the region in the hydrogen electrode layer 6 other than the first region 6a, that is, the regions on both sides of the first region 6a, is the second region 6b.

[0050] Here, the average particle size of Ni in the second region 6b is smaller than that in the first region 6a. Therefore, the Ni in the second region 6b has higher activity compared to that in the first region 6a. Accordingly, compared to the first region 6a, the electrode activity in the second region 6b, where the temperature is easily reduced by heat dissipation and the feed gas is difficult to supply from the connecting hole 11, can be improved. Therefore, the difference in electrode activity between the first region 6a and the second region 6b can be reduced, suppressing the current distribution between them, and thus suppressing the degradation of the hydrogen electrode layer 6.

[0051] Furthermore, conventionally, the electrode activity in the second region 6b decreases due to the temperature drop caused by heat dissipation, resulting in a slower H2 generation rate and a tendency for the H2O concentration to rise. If the H2O concentration increases, the growth rate of the oxide film on the surface of the metal support 10 increases, making it difficult for current to flow through the second region 6b and increasing the current distribution. In this embodiment, by reducing the average particle size of Ni in the second region 6b, the electrode activity can be improved. As a result, the H2 generation rate is maintained, thus suppressing the increase in current distribution.

[0052] It should be noted that, unlike fuel cells where an exothermic reaction occurs, the temperature of the second region 6b is more easily reduced in the single electrolytic cell 1 where an endothermic reaction occurs. Furthermore, in the single electrolytic cell 1, by reducing the average particle size of Ni, its function as a thermal catalyst for Ni can be improved. Therefore, the aforementioned effects are particularly effective in the single electrolytic cell 1.

[0053] The average particle size of Ni contained in the first region 6a is not particularly limited, and can be greater than 3 μm and less than 10 μm. The average particle size of Ni contained in the second region 6b is not particularly limited, and can be greater than 1 μm and less than 7 μm.

[0054] The average particle size of Ni contained in the first region 6a was calculated using the following method. First, the cross-section of the hydrogen electrode layer 6 along the Z-axis was exposed. Next, using a SEM apparatus (FE-SEM JSM-7900F manufactured by Nippon Electron Ltd.) and the EDS apparatus (JED-2300) attached to the SEM apparatus, Ni mapping images were acquired at 5000 to 10000x magnification at three locations: any position on the first connecting hole 11a, any position on the second connecting hole 11b, and the center of the first region 6a in the surface direction. These images divided the first region 6a into six equal parts along the thickness direction. Fifteen Ni mapping images were then acquired. Next, using Image-Pro image analysis software manufactured by MEDIACYBERNETICS, binarization was performed to determine the Ni particle portion in each Ni mapping image. Fifteen analytical images were then acquired. Finally, in each binarized analytical image, the diameter of a circle with an area equal to the area of ​​each Ni particle was obtained as the particle size of each Ni particle. Then, the arithmetic mean of the Ni particle size obtained from 15 analytical images was calculated to determine the average Ni particle size contained in the first region 6a.

[0055] It should be noted that in this specification, the thickness direction is a direction perpendicular to the direction of the surface parallel to the first principal surface 12 of the metal support 10. When the thickness direction is determined, an approximate straight line of the first principal surface 12, obtained using the least squares method, is used in the cross-section of the metal support 10 along the Z-axis direction.

[0056] The average particle size of Ni contained in the second region 6b was calculated using the same method as that used for the average particle size of Ni contained in the first region 6a. However, Ni mapping images were obtained at two points where each of the second regions 6b located on both sides of the first region 6a was divided into three equal parts along the surface direction, and at five points where the second regions 6b were divided into six equal parts along the thickness direction. Therefore, 20 Ni mapping images were used when calculating the average particle size of Ni contained in the second region 6b. In addition, the 20 Ni mapping images were obtained on the cross-section of the hydrogen pole layer 6 used when calculating the average particle size of Ni contained in the first region 6a.

[0057] The porosity of the second region 6b is preferably greater than that of the first region 6a. This improves gas diffusion in the second region 6b, where raw material gas is less readily supplied from the connecting holes 11, thereby further enhancing the electrode reaction in the second region 6b. Consequently, current distribution between the first region 6a and the second region 6b can be further suppressed, thus further suppressing the deterioration of the first electrode layer 6.

[0058] There are no particular restrictions on the porosity of the first region 6a; it can be above 20% and below 40%. There are no particular restrictions on the porosity of the second region 6b; it can be above 25% and below 50%.

[0059] The porosity of the first region 6a was calculated using the following method. First, the cross-section of the hydrogen pole layer 6 along the Z-axis was exposed. Next, a backscattered electron image of the cross-section of the first region 6a was acquired at 10,000x magnification using the aforementioned SEM apparatus. Then, using Image-Pro image analysis software manufactured by MEDIACYBERNETICS, the portions displayed in black (corresponding to pores) in the backscattered electron image were identified. Finally, the total area of ​​the pores was divided by the entire area of ​​the backscattered electron image of the first region 6a, thereby calculating the porosity of the first region 6a.

[0060] The porosity of the second region 6b is calculated in the same way as that of the first region 6a, by dividing the total area of ​​the pores by the total area of ​​the backscattered electron image of the second region 6b.

[0061] The hydrogen electrode layer 6 is fabricated as follows: after forming a first region 6a on the metal support 10 using the material used for the first region, a second region 6b is formed by using the material used for the second region to surround the first region 6a, thereby fabricating the hydrogen electrode layer 6. There are no particular limitations on the methods for forming the first and second regions 6a and 6b; methods such as firing, spraying (spraying, aerosol deposition, aerosol vapor deposition, powder jet deposition, particle jet deposition, cold spraying, etc.), PVD (sputtering, pulsed laser deposition, etc.), and CVD can be used.

[0062] [Electrolyte layer 7]

[0063] Electrolyte layer 7 is disposed between hydrogen electrode layer 6 and oxygen electrode layer 9. In this embodiment, an anti-reaction layer 8 is disposed between electrolyte layer 7 and oxygen electrode layer 9. Therefore, electrolyte layer 7 is disposed between hydrogen electrode layer 6 and anti-reaction layer 8, and is connected to hydrogen electrode layer 6 and anti-reaction layer 8 respectively.

[0064] The electrolyte layer 7 covers the hydrogen electrode layer 6 and also covers the area of ​​the first main surface 12 of the metal support 10 exposed from the hydrogen electrode layer 6.

[0065] Electrolyte layer 7 allows O2 generated in hydrogen electrode layer 6 to pass through. － It is transferred to the oxygen electrode layer 9 side. The electrolyte layer 7 is made of a dense material with oxide ion conductivity. The electrolyte layer 7 can be made of, for example, YSZ (yttrium-stabilized zirconium oxide, such as 8YSZ), GDC (gadolinium-doped cerium oxide), ScSZ (scandium-stabilized zirconium oxide), SDC (samarium-solution cerium oxide), LSGM (lanthanum gallium oxide), etc.

[0066] There are no particular limitations on the porosity of the electrolyte layer 7; for example, it can be above 0.1% and below 7%. There are no particular limitations on the thickness of the electrolyte layer 7; for example, it can be above 1 μm and below 100 μm.

[0067] There are no particular restrictions on the method of forming the electrolyte layer 7; methods such as sintering, spraying, PVD, and CVD can be used.

[0068] [Anti-reaction layer 8]

[0069] An anti-reaction layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9. The anti-reaction layer 8 is positioned on the opposite side of the hydrogen electrode layer 6, with the electrolyte layer 7 as a reference. The anti-reaction layer 8 inhibits the reaction between the constituent elements of the electrolyte layer 7 and the constituent elements of the oxygen electrode layer 9, thus preventing the formation of a layer with high electrical resistance.

[0070] The anti-reaction layer 8 is made of an oxide ion-conducting material. The anti-reaction layer 8 can be composed of GDC, SDC, etc.

[0071] There are no particular limitations on the porosity of the anti-reaction layer 8; for example, it can be 0.1% or more and less than 50%. There are no particular limitations on the thickness of the anti-reaction layer 8; for example, it can be 1 μm or more and less than 50 μm.

[0072] There are no particular restrictions on the method of forming the anti-reaction layer 8; methods such as firing, spraying, PVD, and CVD can be used.

[0073] [Oxygen layer 9]

[0074] The oxygen electrode layer 9 is disposed on the opposite side of the hydrogen electrode layer 6, with the electrolyte layer 7 as a reference. In this embodiment, an anti-reaction layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9, thus the oxygen electrode layer 9 is connected to the anti-reaction layer 8. Without the anti-reaction layer 8 disposed between the electrolyte layer 7 and the oxygen electrode layer 9, the oxygen electrode layer 9 is connected to the electrolyte layer 7. The oxygen electrode layer 9 is an example of the "second electrode layer" of the present invention.

[0075] Oxygen electrode 9 is supplied with O2 from hydrogen electrode 6 via electrolyte layer 7 according to the chemical reaction described in equation (2) below. － O2 is generated.

[0076] ·Oxygen layer 9: 2O2 － →O2+4e － ···(2)

[0077] The oxygen electrode layer 9 is composed of a porous material with oxide ion conductivity and electronic conductivity. The oxygen electrode layer 9 may be composed of a composite material of one or more of (La,Sr)(Co,Fe)O3, (La,Sr)FeO3, La(Ni,Fe)O3, (La,Sr)CoO3, and (Sm,Sr)CoO3 with an oxide ion-conducting material (GDC, etc.).

[0078] There are no particular limitations on the porosity of the oxygen electrode layer 9, for example, it can be above 20% and below 60%. There are no particular limitations on the thickness of the oxygen electrode layer 9, for example, it can be above 1 μm and below 100 μm.

[0079] There are no particular restrictions on the method of forming the oxygen electrode layer 9; methods such as firing, spraying, PVD, and CVD can be used.

[0080] [Flow path component 30]

[0081] The flow path component 30 is joined to the second main surface 13 of the metal support 10. The flow path component 30 forms a flow path 30a between itself and the metal support 10. A raw material gas is supplied to the flow path 30a. The raw material gas supplied to the flow path 30a is supplied to the hydrogen electrode layer 6 of the single cell body 20 through the connecting holes 11 of the metal support 10.

[0082] The flow path component 30 can be made of, for example, an alloy material. The flow path component 30 can also be formed of the same material as the metal support 10. In this case, the flow path component 30 can be substantially integrated with the metal support 10.

[0083] The flow path component 30 has a frame 31 and an interconnector 32. The frame 31 is an annular component that surrounds the sides of the flow path 30a. The frame 31 is joined to the second main surface 13 of the metal support 10. The interconnector 32 is a plate-shaped component for connecting an external power source or other electrolytic cells in series with the electrolytic cell 1. The interconnector 32 is joined to the frame 31.

[0084] In this embodiment, the frame 31 and the interconnector 32 are separate components; however, the frame 31 and the interconnector 32 can be an integral component.

[0085] (Modifications of the implementation method)

[0086] The embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments, and various modifications can be made as long as they do not depart from the spirit of the present invention.

[0087] [Variation 1]

[0088] A portion of the hydrogen electrode layer 6 can enter each of the connecting holes 11 of the metal support 10. In the above embodiment, the first region 6a of the hydrogen electrode layer 6 is the region where the hydrogen electrode layer 6 is formed on the permeable region 10a of the metal support 10. Therefore, the region of the hydrogen electrode layer 6 that enters the connecting holes 11 is not included in the second region 6b of the hydrogen electrode layer 6.

[0089] [Variation 2]

[0090] In the above embodiment, the case where the average particle size of Ni contained in the second region 6b in one cross-section of the hydrogen electrode layer 6 is smaller than the average particle size of Ni contained in the first region 6a was described. Although this configuration is preferably observable in all cross-sections of the hydrogen electrode layer 6, it is acceptable if it can be observed in at least one cross-section of the hydrogen electrode layer 6. This is because if it is observed in one cross-section, then at least in that location, the degradation of the hydrogen electrode layer 6 can be suppressed.

[0091] [Variation Example 3]

[0092] In the above embodiments, an electrolytic single cell 1 was described as an example of an electrochemical single cell; however, electrochemical single cells are not limited to electrolytic single cells. An electrochemical single cell is a general term for an element that has a pair of electrodes arranged in such a way that an electromotive force is generated by an overall redox reaction to convert electrical energy into chemical energy, and an element used to convert chemical energy into electrical energy. Therefore, electrochemical single cells include, for example, fuel cells that use oxide ions or protons as carriers.

[0093] Symbol Explanation

[0094] 1 Electrolytic single cell

[0095] 10 Metal Support

[0096] 11 connecting holes

[0097] 12 First Main Page

[0098] 13 Second Main Face

[0099] 20 Single Battery Main Body

[0100] 6-Hydrogen Polar Layer

[0101] 7 Electrolyte layer

[0102] 8 anti-reaction layers

[0103] 9 oxygen polar layers

[0104] 30 flow path components

[0105] 30a flow path

Claims

1. An electrochemical single cell, comprising: A metal support having a breathable area with multiple interconnected holes and an impermeable area that surrounds the breathable area when viewed from above. as well as A single-cell main body is disposed on the metal support. The main body of the single battery has: A first electrode layer, the first electrode layer containing Ni; Second electrode layer; as well as An electrolyte layer is disposed between the first electrode layer and the second electrode layer. The first electrode layer has: a first region formed on the breathable region, and a second region formed on the impermeable region. The average particle size of Ni contained in the second region is smaller than that of Ni contained in the first region.

2. The electrochemical single cell according to claim 1, wherein, The porosity of the second region is greater than that of the first region.

3. The electrochemical single cell according to claim 1 or 2, wherein, The first electrode layer is a hydrogen electrode in which H2 is generated from a raw material gas containing H2O.

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